A Cadbury workers union held constructive talks with U.S. suitor Kraft Foods after the two sides met to discuss jobs, pensions and working conditions on Wednesday, a union official said.

Britain's biggest union Unite, which has 2 million members, met executives from Kraft's European management team in London after the union had written to Kraft CEO Irene Rosenfeld seeking assurances if Kraft succeeds in taking over the UK confectionery firm.

The meeting was productive. We discussed the issues we laid out in the letter and hopefully they listened, said Jennie Formby, Unite's national officer for the food industry, who attended the meeting.

They were keen to say they did not have enough information to give us firm assurances at this stage. But we are committed to further talks, as we are prepared to talk to all potential bidders for Cadbury, she added.

Formby said no date had been set for the next meeting with Kraft.

When Kraft went public with its interest in Cadbury in early September, it said it hoped to reverse Cadbury's plans to close its Somerdale sweet factory near Bristol in southwest England and also invest in Cadbury's main British plant at Bournville.

Kraft launched its official cash and shares bid earlier this month. The bid currently values Cadbury shares at 722 pence, or the company at 9.9 billion pounds ($16.4 billion). By 1347 GMT Cadbury shares were at 807-1/2p, above the offer price on hopes that rival interest that might push Kraft to raise its offer to succeed.

Italy's Ferrero and U.S. based Hershey Co have said separately they are considering making bids for Cadbury, while Switzerland's Nestle has been mentioned by analysts as a possible partner for Hershey should the U.S. group decide to bid.

Cadbury announced in 2007 that its Somerdale plant would close by 2010 with 500 job losses and that Bournville will lose 200 jobs by 2010 as the group shifts production to Poland as part of a strategy to drive sales growth and boost margins.

The Somerdale factory in the town of Keynsham near Bristol is expected to close completely towards the end of 2010.

Kraft itself closed its Terry's factory in York, northern England, in 2005 with the loss of over 300 jobs to end over 200 years of chocolate making as the manufacture of Terry's chocolate oranges and All Gold moved to Kraft plants in Sweden, Belgium, Poland and Slovakia.

($1=.6045 pounds)

(Editing by Mike Nesbit)